Treat an empty features string as a no-op like Cargo does (#566)

* Treat an empty features string as a no-op like Cargo does

* Remove empty features everywhere

* Update tests, don't use Default

* Looks like clap doesn't like keeping things simple :(

* Don't need a patch anymore with this version

src/lib.rs

@@ -27,7 +27,7 @@ pub use query::{ActualSemverUpdate, RequiredSemverUpdate, SemverQuery};
 
 /// Test a release for semver violations.
 #[non_exhaustive]
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Check {
     /// Which packages to analyze.
     scope: Scope,
@@ -52,7 +52,7 @@ pub enum ReleaseType {
 }
 
 #[non_exhaustive]
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 pub struct Rustdoc {
     source: RustdocSource,
 }
@@ -102,7 +102,7 @@ impl Rustdoc {
     }
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 enum RustdocSource {
     /// Path to the Rustdoc json file.
     /// Use this option when you have already generated the rustdoc file.
@@ -120,12 +120,12 @@ enum RustdocSource {
 }
 
 /// Which packages to analyze.
-#[derive(Default, Debug)]
+#[derive(Default, Debug, PartialEq, Eq)]
 struct Scope {
     mode: ScopeMode,
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 enum ScopeMode {
     /// All packages except the excluded ones.
     DenyList(PackageSelection),
@@ -140,7 +140,7 @@ impl Default for ScopeMode {
 }
 
 #[non_exhaustive]
-#[derive(Default, Clone, Debug)]
+#[derive(Default, Clone, Debug, PartialEq, Eq)]
 pub struct PackageSelection {
     selection: ScopeSelection,
     excluded_packages: Vec<String>,

src/main.rs

@@ -121,7 +121,7 @@ enum SemverChecksCommands {
     CheckRelease(CheckRelease),
 }
 
-#[derive(Debug, Args)]
+#[derive(Debug, Args, Clone)]
 struct CheckRelease {
     #[command(flatten, next_help_heading = "Current")]
     pub manifest: clap_cargo::Manifest,
@@ -340,8 +340,15 @@ impl From<CheckRelease> for cargo_semver_checks::Check {
         let mut baseline_features = value.baseline_features;
         current_features.append(&mut mutual_features.clone());
         baseline_features.append(&mut mutual_features);
-        check.with_extra_features(current_features, baseline_features);
 
+        // Treat --features="" as a no-op like cargo does
+        let trim_features = |features: &mut Vec<String>| {
+            features.retain(|feature| !feature.is_empty());
+        };
+        trim_features(&mut current_features);
+        trim_features(&mut baseline_features);
+
+        check.with_extra_features(current_features, baseline_features);
         check
     }
 }
@@ -351,3 +358,22 @@ fn verify_cli() {
     use clap::CommandFactory;
     Cargo::command().debug_assert()
 }
+
+#[test]
+fn features_empty_string_is_no_op() {
+    use cargo_semver_checks::Check;
+
+    let Cargo::SemverChecks(SemverChecks {
+        check_release: no_features,
+        ..
+    }) = Cargo::parse_from(["cargo", "semver-checks"]);
+
+    let empty_features = CheckRelease {
+        features: vec![String::new()],
+        current_features: vec![String::new(), String::new()],
+        baseline_features: vec![String::new()],
+        ..no_features.clone()
+    };
+
+    assert_eq!(Check::from(no_features), Check::from(empty_features));
+}

src/rustdoc_gen.rs

@@ -229,7 +229,7 @@ pub(crate) enum CrateType<'a> {
 
 /// Configuration used to choose features to enable.
 /// Separate configs are used for baseline and current versions.
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, PartialEq, Eq)]
 pub(crate) struct FeatureConfig {
     /// Feature set chosen as the foundation.
     pub(crate) features_group: FeaturesGroup,
@@ -238,7 +238,7 @@ pub(crate) struct FeatureConfig {
     pub(crate) is_baseline: bool,
 }
 
-#[derive(Debug, Clone, Serialize)]
+#[derive(Debug, Clone, Serialize, PartialEq, Eq)]
 pub(crate) enum FeaturesGroup {
     All,
     Default,